Regional differences in leprosy; leprosy among Chinese in Malaya

This is an interesting comparison between the types of leprosy seen among Chinese, Malays and Indians in Malaya, based on a large experience. The disease is most virulent among Chinese and least so among Indians, three-fourths of the cases among the latter being of mild tuberculoid disease with a tendency to self-healing, but among the Chinese only one-third are of the tuberculoid type. The climate of Malaya is of the hot humid type, in which leprosy flourishes. On the other hand, a higher standard of living than in India tends to hinder the spread of the disease. The age incidence is important. Among, the Chinese, early macules are commonly found in children of 5 to 15 years of age, most of which tend to clear up, but in about one-fourth tuberculoid lesions develop and may go on to the lepromatous condition, especially if the onset of the tuberculoid stage occurs early. When a reliable history is obtained in Chinese, in nearly every lepromatous case a tuberculoid stage was first observed, commonly in the age group 16-40. In a smaller number of persons of over 40 years of age, the proportion of tuberculoid cases is very much higher, but the tendency to become lepromatous is very much less. Major tuberculoid cases are more liable than minor to become lepromatous, but nerve thickening in tuberculoid leprosy is less evident in Chinese than in Indians and it is rare in children and in those over 40. In view of the foregoing peculiarity of the evolution of leprosy in tuberculoid cases in Chinese subjects, active treatment is necessary, in order to prevent them becoming lepromatous. For this purpose, intradermal injections are of little value and they tend to obscure any evolutionary changes. Hydnocarpus oil or esters (deep subcutaneous injections) should therefore be pushed to the limit of tolerance in doses of 1 cc. per 10 pounds body weight twice weekly, or 30 cc. per week, for a patient of 150 Ibs. as a minimum and increased by at least fifty per cent, in acute or reacting cases, when improvement may be expected within three months. Some years' experience of this intensive treatment as compared with weekly injections of 1-5 cc. has shown much more marked improvement and much less incidence of lepromatous change with the high doses. In lepromatous cases, reactions should be avoided, but dosage should be as high as possible short of producing increased erythrocyte sedimentation and plantar pain on heavy stroking. Surveys of school children are of great importance in finding the early macular stage and their discovery may lead to the detection of infective adults who require to be segregated. L. Rogers.